Confirmed 15/02/2017. Geosynchronous Warehouse buyout cost 829 BC with 'Haidar the Tracker' leader with +15% Buyout Cost REDUCTION, removed him from system and the buyout cost dropped to its base cost of 720 BC.

On the PC calculator, 720 x 1.15 = 828. To confirm this I also performed the inverse calculation of: 829 / 1.15 = 720.869, rounded to 721, which is still also wrong (by only 1 BC, but still, come on Wargaming)

So not only did they get 'reduction' confused with 'increase', they also got some basic maths wrong.